字幕列表 影片播放 列印英文字幕 Want to speak real English from your first lesson? Sign up for your free lifetime account at englishclass101.com. Hi, everybody. My name is Alisha. Today, I'm going to talk about how to use the word “could” to express possibility and a few other uses of this word too. So, let's get started. Okay, the first use of “could” that I want to mention is as the past tense of “can.” So, “can” is the present tense word we use to talk about ability, we use it for ability. However, in the past tense “can” becomes “could.” That means we use the word, “could,” to express past ability. Let's look at some example sentences. First one, “When I was young I could speak Spanish.” So, a past tense situation, this is a past ability. “I could speak Spanish.” “Three years ago, she could swim faster than all the other students in her class.” So, again a past tense situation, three years ago here. Okay, one more. “Last week, I couldn't use this software. Now, I can.” So, here, I've used the negative “couldn't,” could not. “Last week, I couldn't use this software. Now, I can.” So, I used “can” in the present tense here. So, that's the first point that I want to mention for today. Using “could” as the past tense of the word, “can.” So, these all express past ability, a past capability. The second point I want to talk about for today is using “could” for suggestions and for advice. Please keep in mind when you use “could,” it's not giving maybe a promise about that activity. You're not making any promises about the activity. The nuance of “could” or the meaning of “could” is just possibility. When you give a suggestion or when you give advice, using the word, “could,” you're giving some information about possibility only. Something it is possible to do, an action it is possible to take. Let's look at some examples then. First, “We could go hiking this weekend.” Here, I have “could.” So, again, just a possibility. “It's possible to go hiking this weekend,” “we could.” So, this is a suggestion for a possible action. Next, “I could cook something spicy for dinner tonight.” Again, possibility only. “I could cook something spicy for dinner.” It's possible for me to make something spicy. Third, “You could try talking to your landlord about the problem.” So, here, I have the word, “could.” Again, it's possible you could talk to your landlord. It's possible, you could. So, we can think of these two things as having a very similar meaning. Keep in mind, of course, because this is a suggestion, if I suggest, for example, “I could cook something for dinner tonight,” the nuance is that maybe the speaker wants to do that activity or recommends that activity or that action. But, the nuance once, again, is just that it's possible, just that it's possible. So, it's a fairly soft recommendation. Okay, so that's point number two I want to mention. Before I go to point number three, I want to mention two kinds of smaller points within this. First, when we use “could” in the positive like I've used here, “She could swim,” or, “We could go hiking,” for example, this refers to something that is possible. It is something that is possible to do. In the negative form, however, like “could not,” for example, in this sentence, “Last week, I couldn't use this software.” When we use it in the negative form, it means impossible, 0% chance. Positive is just something possible. There's potential for an action to happen or for a status, but, impossible is the negative form. It is totally impossible, zero chance of something. So, with these points in mind, let's look at the next item I want to talk about. Okay. So, we can use “could” and “be,” the verb, “to be,” for a status. So, a situation like to talk about a person or to talk about a thing. So, again, this expresses a possibility. We are making a guess. So, in these cases, we don't have all the information about a situation but we are making a guess, a guess about potential, a guess about possibility. For example, “This could be the right house.” If you've seen the video we did about using “must,” you'll notice maybe I've used a similar sentence here. “This could be the right house,” and “This must be the right house.” They're very similar sentences. “Could” expresses only possibility, so a lower level of certainty than “must.” If I say, “This must be the right house,” it means there's a very high chance this is the correct house. Here, “could” shows only possibility, so a lower level of chance, there's not so much certainty here. Let's look at another one. “He couldn't be my teacher. I heard my teacher wears glasses.” Here, I have the negative, “couldn't,” “He couldn't be my teacher.” That implies it is impossible. So, “That person, that man, couldn't be my teacher because I heard my teacher wears glasses.” So, I have some other information that tells me, “This person, this guy, he couldn't be my teacher. It's not possible for him to be my teacher.” One more example. “They could be asleep, maybe that's why they're not answering the phone.” So, here, I've used positive “could,” “They could be asleep,” so I'm showing only possibility here. I'm giving a possible explanation for why these people are not answering their phone. “They could be asleep.” It's possible they are asleep. Okay. Now, let's consider how to explain points like this but in the past tense. So, when we make the past tense, we use “have” and the past participle of a verb. So, for example, “She couldn't have been on the airplane.” “She couldn't,” again, impossible, “It was impossible she was on the airplane.” “She couldn't have been on the airplane,” maybe her first flight was delayed. It's impossible. It was impossible for her to be on the airplane. Another example, “This could have been finished faster.” I have the positive here showing it's possible. So, a project, for example, it's possible that this project, maybe, “could.” It's possible to have been finished faster here. So, again, the positive form shows only possibility and here in the past, “could have been finished faster.” One more, “I could've.” Here, I've used the contracted form. So, “could” plus “have” become “could've.” So, “I could've gotten up earlier.” Maybe I got up at 10 o'clock but 8 o'clock was possible in the past. “I could have,” meaning maybe I didn't but it was possible in the past. We can use “could've” to show that. Okay. The final point I want to make today is about future situations. Making guesses about future situations. Just a couple of examples here. Remember, the same positive and negative point applies here as well. So, in the first example, “I have your mom could call while we're out.” “Your mom could,” and then I have a verb after this, “call,” to call, make a phone call. So, “Your mom could call while we're out,” meaning, in the future, when we are out of the house, it's possible your mother may call. This is the nuance of this expression. So, I'm making a guess about a future situation with the word, “could.” “Your mother could call while we're out.” We can use it in another situation. “He could send the file before the meeting.” So, again, these are guesses, both cases, your mom and this, he, person, these are guesses about other people. We're making a guess about a future situation, a future possible situation. So, “He could send the files before the meeting,” but we don't know. We're making a guess about the future. You can use “could” to express that as well. So, those are a few different points about how to use the word “could.” We can use it as the past tense of “can.” We can use it to make suggestions and to give advice. We can use it to talk about a status, a possibility around a status. And, we can use it to talk about the past situations, past possible situations. And, finally, to make guesses about future possible situations too. So, this is a lot of information and it's very quick but I hope that it was useful for you. If you have any questions or comments, please feel free to let us know in the comment section below this video. If you liked this video please make sure to subscribe to our channel and hit the Like button on this video, as well. Check us out at EnglishClass101.com for more good stuff too. Thanks very much for watching this episode and I will see you again soon. Bye.